The Xoloitzcuintli -- or show-low, as it is commonly called -- is the national dog of Mexico. Previously known as the Mexican Hairless, it comes in three sizes as well as a coated version, seen in the show ring only in the US and Canada. These dogs descend from hairless dogs prized by the Aztecs and revered as guardians of the dead. More than 400 years later, these dogs were still to be found in the Mexican jungles. Shaped by the environment rather than by man, their keen intelligence, trainability and natural cleanliness have made them a unique and valued pet today.